Not sure as to the direction of your question, if you mean about the world economy in general or the state of the markets?
If you mean the state of the Stock Markets then no I am not worried. They tend to over-react in most cases. I will continue buying in what I see as good opportunities as the markets fall. That has been successful for me in the past. Even with this last weeks sell offs I am still above the levels where I was at the start of the 2007-8 crash, and far above the lowest levels of March 2010.
I am a lot more concerned over the government reactions around the world though. Many governments are on the brink of collapse and financial problems abound both in the US and elsewhere.
The recent brinkmanship of the US government in particular is cause for concern. The question of default should never have arisen and having solved the problem the legislators pack up for a vacation, while problems continue, eg FAA layoff.
The uncertainty in world markets is a boon for me as an investor as I can find more bargains at good prices. The problem is making markets unstable this way is going to lead to as one commentator said a "Game of Russian Roulette where the gun goes off by acciddent."